A fortnight after starting, employees can opt out and have a further six weeks to do so.
If you opt out within that two-to-eight week, post-join-up period, any payments will be refunded to the employee and employer by the IRD.
Once you belong to KiwiSaver, as an employee, everything you earn has KiwiSaver taken out - including things like Christmas bonuses.
The law is also clear it is up to the employer to get it right.
"If the employee belongs to KiwiSaver and KiwiSaver deductions are not being made from his salary and the employer is not contributing at least 3 per cent as well, the employer is in the wrong and is doing something illegal.
"The employer would be liable to pay that backpay, plus interest to the employee," says Partridge.
Obviously these rules don't apply to anyone who has chosen to take a contributions holiday.
When you start KiwiSaver contributions, it can take up to three months for it to appear in your account at your provider - IRD pays interest of 2.35 per cent on any money it holds - but that isn't likely here, given you started your new job more than nine months ago.
Talking to your employer is probably the best first step - it may be a genuine mistake.
The IRD it is also able to send a letter to your employer, reminding it of its obligations.
Technology may prove to be a winner in sorting out missed payments in the future.
The IRD is consulting on changes aimed at improving the collection of PAYE information and deductions from employees, including income tax, KiwiSaver contributions and any other deductions such as student loan repayments, says a spokesperson.
"It is proposed that greater use of digital technology can help make the PAYE system more accurate and efficient."